1. Field of the Intention
An aspect of the present invention relates to a method for forming a pattern and a method for manufacturing a semiconductor device.
2. Description of the Related Art
With the progress of scaling-down of semiconductor integrated circuits and increase in scale of the integration, it has been demanded to increase the accuracy of photolithography apparatus in the field of a pattern transfer technique to realize microfabrication. On this account, the cost involved in such apparatus has been increasing, which has been a disadvantage.
As a technique to form a fine pattern at low cost, the photo-nanoimprint technique has been proposed (see e.g. JP-2000-194142-A). This is a technique to transfer a resist pattern by: pressing a stamper, i.e. a template having the projection-and-reentrant pattern that corresponds to a pattern to be formed on a substrate, against a photo-curable organic material layer formed on a surface of a substrate targeted for transfer; applying rays of light through the template to cure the organic material layer in this condition; and then separating the template from the organic material layer.
The organic material layer, which serves as a resist, is applied to the targeted surface, during which the operation is controlled so that the organic material is spread reaching every nook and cranny of the projection-and-reentrant pattern on the template. In an area where the template overlaps with an edge of a substrate when the template is pressed against the substrate, it is usually difficult to keep the template in parallel with the surface of the substrate. Therefore, the organic material is not put on such area, to which no pattern is transferred.
In regard to the vicinity of the periphery of a pattern transfer area, no pattern is formed in a peripheral area of a wafer substrate, which poses problems including the following defects. The first is the abnormality in a processing form arising near the periphery of the pattern transfer area under the influence of the change in pattern coverage in an etching step after imprinting. The second is the exfoliation of a wire in a process of CMP (Chemical Mechanical Polishing) after burying the wire in position.